Quote Originally Posted by eva2000 View Post
When it doesn't boot what postled code ?
I usually get one of two codes: 75 or 88. When it's 88 I can't use the reset/power buttons to reset the CMOS. I have to turn power off at the PSU. Sometimes this takes a couple of times before it boots again. If it is 75 then I can reboot using the reset/power switches.

play with PWM switch frequencies as well some memory like reduce 15% over nominal
This didn't make any difference as far as I can tell.

and play with modules in different order for same dimm slots
Didn't help.

also play with subtimings too
See below.

DRAM memory tips #1, #2 and #3 http://i4memory.com/102537-post3.html
Thanks.

Also have you tried bclk values other than 173 ? i.e. 174 or higher ?
Yes. 174, 175, 180, 190 and others that I've forgotten.

I'm using 1/23 pre-beta bios and first time i came across this little bug i was testing 6x1GB mixed tri channel and 7-7-7-18 1t and slowly bumping bclk on 8x mem multi. Was fine from starting bclk of 150 up to 166. Then set 167 got postled 75 on bios exit/boot up and blank screen. Then tried bclk from 168 to 216 and had no probs with 6x1GB @859mhz 7-7-7-18 1T http://i4memory.com/f83/6x1gb-corsai...rclocks-14112/ heh
I flashed to the 1/23 pre-beta bios. I then kinda through in the towel. I've swapped memory. I'm now using my dual channel Corsair DDR3-2133 so I'm going to start over with this memory.

So in your case (and anyone else reading):

  1. Find the limits of your memory before you find limits of your cpu/bclk.
  2. Find out what your memory can do on each mem multiplier/cpu multi combination.
  3. Find out what voltages your memory likes and what's the optimal voltage difference between vdimm and uncore (cpu vtt) for your particular ram/setup
  4. Find out whether the ram likes pwm switch frequencies of reduce 15% or nominal.
  5. Find out which of your modules likes which dimm slot 2 or 4 or 6.
  6. Found out what auto subtimings translate to in cpu tweaker or memset at each mem frequency/timing combination.

Trust me when I say figuring out ram side will make overclocking the cpu much easier
I was doing something close to this but it's nice to be reminded.

Here's the DRAM timing listed in the BIOS. Which of the subtimings to you set?

DRAM Timing | CPU-Tweaker (Yes/No)
------------------------------------
DRAM Command Rate: 1N | Yes
CAS Latency Time (tCL): 9 | Yes
RAS# to CAS# Delay (tRCD): 9 | Yes
RAS# Precharge (tRP): 9 | Yes
Precharge Delay (tRAS): 24 | Yes
REF to ACT Delay (tRFC): AUTO | Yes
Write to PRE Delay (tWR): AUTO | Yes
Rank Write to Read (tWTR): AUTO | > Tip #3: Write to Read (Same Rank)
ACT to ACT Delay (tRRD): AUTO | Yes
Row Cycle Time (tRC): AUTO | No ?
Read CAS# Precharge (tRTP): AUTO | Yes
Four ACT WIN Time (tFAW): AUTO | No ?